The goal of this project is to establish a database for comparative neuroanatomy of primates using high resolution magnetic resonance imaging (MRI). Thus far, 44 animals have been scanned, including representatives of every species listed above and all of these scans have been reconstructed to provide surface rendering and volumetric measures of whole brain and whole cerebellum. A technique for gray matter/white matter segmentation has been developed and applied to analyze these volumes separately. Results to date indicate 1) a decrease in relative cerebellar volume in humans compared to apes; 2) a decrease in relative corpus callosum size in the human brain; and 3) marked regional expansion of neocortex in the human and ape brains as measured by gyrification. These studies provide the first MRI database for studies of comparative primate brain evolution and should yield novel insights into differences between human and non-human primate neuroanatomy.